Endovascular delivery system with flexible and torqueable hypotube

ABSTRACT

A medical device includes an elongate metallic hypotube having an open proximal end and an opposed open distal end defining a tubular wall having an open internal diameter and an exterior diameter. The tubular wall has a first flexible portion disposed near the proximal open end and a second portion disposed near the distal open end. The first flexible portion of the hypotube includes a plurality of slots extending through the tubular wall and having a circumferential arc from about 150° to about 300°; and where adjacent slots are axially offset from one and the other from about 30° to about 60°. The medical device may be used as part of an endovascular delivery system.

CROSS-REFERENCE TO RELATED APPLICATIONS:

This application is a continuation of U.S. patent application Ser. No.13,803,062, filed Mar. 14, 2013, which claims the benefit of U.S.Provisional Application No. 61/660,103, filed Jun. 15, 2012, thecontents of which are incorporated by reference herein.

FIELD OF THE INVENTION

The present invention is related to an endovascular delivery system foran endovascular prosthesis. More particularly, the present invention isrelated to an endovascular delivery system having a slotted hypotube forflexibility and torqueability for an inflatable and bifurcatedendovascular prosthesis.

BACKGROUND OF THE INVENTION

An aneurysm is a medical condition indicated generally by an expansionand weakening of the wall of an artery of a patient. Aneurysms candevelop at various sites within a patient's body. Thoracic aorticaneurysms (TAAs) or abdominal aortic aneurysms (AAAs) are manifested byan expansion and weakening of the aorta which is a serious and lifethreatening condition for which intervention is generally indicated.Existing methods of treating aneurysms include invasive surgicalprocedures with graft replacement of the affected vessel or body lumenor reinforcement of the vessel with a graft.

Surgical procedures to treat aortic aneurysms can have relatively highmorbidity and mortality rates due to the risk factors inherent tosurgical repair of this disease as well as long hospital stays andpainful recoveries. This is especially true for surgical repair of TAAs,which is generally regarded as involving higher risk and more difficultywhen compared to surgical repair of AAAs. An example of a surgicalprocedure involving repair of a AAA is described in a book titledSurgical Treatment of Aortic Aneurysms by Denton A. Cooley, M.D.,published in 1986 by W.B. Saunders Company.

Due to the inherent risks and complexities of surgical repair of aorticaneurysms, endovascular repair has become a widely-used alternativetherapy, most notably in treating AAAs. Early work in this field isexemplified by Lawrence, Jr. et al. in “Percutaneous Endovascular GraftExperimental Evaluation”, Radiology (May 1987) and by Mirich et al. in“Percutaneously Placed Endovascular Grafts for Aortic Aneurysms:Feasibility Study,” Radiology (March 1989). Commercially availableendoprostheses for the endovascular treatment of AAAs include theEndurant™ and Talent™ Abdominal Stent Grafts sold by Medtronic, Inc. ofMinneapolis, Minn.; the Zenith Flex® AAA Endovascular Graft and theZenith TX2® TAA Endovascular Graft, both sold by Cook Medical, Inc. ofBloomington, Ind.; the AFX™ Endovascular AAA system sold by Endologix,Inc. of Irvine, Calif.; and the Gore® Excluder® AAA Endoprosthesis soldby W.L. Gore & Associates, Inc. of Flagstaff, Ariz. A commerciallyavailable stent graft for the treatment of TAAs is the Gore® TAG®Thoracic Endoprosthesis sold by W.L. Gore & Associates, Inc. ofFlagstaff, Ariz.

When deploying devices by catheter or other suitable instrument, it isadvantageous to have a flexible and low profile stent graft and deliverysystem for passage through the various guiding catheters as well as thepatient's sometimes tortuous anatomy. Many of the existing endovasculardevices and methods for treatment of aneurysms, while representingsignificant advancement over previous devices and methods, use systemshaving relatively large transverse profiles, often up to 24 French.Also, such existing systems have greater than desired lateral stiffness,which can complicate the delivery process. In addition, the sizing ofstent grafts may be important to achieve a favorable clinical result. Inorder to properly size a stent graft, the treating facility typicallymust maintain a large and expensive inventory of stent grafts in orderto accommodate the varied sizes of patient vessels due to varied patientsizes and vessel morphologies. Alternatively, intervention may bedelayed while awaiting custom size stent grafts to be manufactured andsent to the treating facility. As such, minimally invasive endovasculartreatment of aneurysms is not available for many patients that wouldbenefit from such a procedure and can be more difficult to carry out forthose patients for whom the procedure is indicated. What have beenneeded are stent graft systems, delivery systems and methods that areadaptable to a wide range of patient anatomies and that can be safelyand reliably deployed using a flexible low profile system.

SUMMARY OF THE INVENTION

In one aspect of the present invention an endovascular delivery systemis provided. The endovascular delivery system may include an elongateouter tubular sheath having an open lumen and opposed proximal anddistal ends with a medial portion therein between; an elongate innermetallic hypotube having a tubular wall with an open lumen and opposedproximal and distal ends with a medial portion therein between, thehypotube having a longitudinal length greater than a longitudinal lengthof the outer tubular sheath, the hypotube being slidably disposed withinthe open lumen of the outer tubular sheath; the distal end of the outertubular sheath being slidably disposed past and beyond the distal end ofthe hypotube to define an endovascular prosthesis delivery state andslidably retractable to the medial portion of the hypotube to define anendovascular prosthesis unsheathed state; where the hypotube furtherincludes: a first flexible portion disposed from about the distal end ofthe hypotube to about the medial portion of the hypotube; a secondportion disposed from about the medial portion of the hypotube to aboutthe proximal end of the hypotube; the first flexible portion of thehypotube including a plurality of slots extending through the tubularwall of the hypotube, the slots having a circumferential arc about thetubular wall from about 150° to about 300°; and where adjacent slots areaxially offset from one and the other from about 30° to about 60°. Thesecond portion of the hypotube may be substantially free of any slots.

The hypotube may be formed from a metallic material, such as 316 or 304stainless steel. In some embodiments, the first flexible portion of thehypotube has a bending radius of at least about 1.5 inches beforeplastic deformation. The tubular wall of the hypotube may have athickness from about 0.005 inches to about 0.020 inches with an externaldiameter of the hypotube is from about 0.080 inches to about 0.260inches. Advantageously, the slots have a kerf width from about 0.001inches to about 0.003 inches.

The longitudinal distance between adjacent slots may be from about 0.010inches to about 0.050 inches and/or from about ⅙ of the exteriordiameter of the hypotube. The hypotube may have a longitudinal lengthfrom about 25 inches to about 40 inches with the flexible portion havinga longitudinal length from about 15 inches to about 32 inches and/orabout from about 50 percent to about 80 percent of the longitudinallength of the hypotube. In some embodiments, the hypotube includes anexterior surface having a surface finish of less than or equal to about32 microinches RMS. The slots may have edges that are rounded to aradius of about 0.005 inches or less.

While the outer tubular sheath may include polymeric material, such aspolytetrafluoroethylene, the hypotube is in some embodiments an uncoatedhypotube free of any polymeric covering or liner.

When the hypotube is disposed within the outer tubular sheath, thehypotube may have a torqueability from about 70% to about 100%, wherethe torqueability is measured as ratio of rotation of the distal end ofthe hypotube for a rotation amount at the proximal end of the hypotube,when placed in a tortuous path, such as an S-shaped path having two fulland opposed 180° bends with a bend radius of about 2 inches. In someembodiments, the torqueability of the hypotube is approximately or about100% or a torqueability of about 1:1.

One particularly useful axial offset of the hypotube slots is about 45°so that the rotation of the device feels smooth when placed in atortuous path, such as the above-described tortuous path. At axialoffset angles greater than about 60°, rotation of the device becomesmore granular which reduces feedback useful for accurate orientation ofthe device during delivery through bodily lumens.

In another aspect of the present invention an endovascular deliverysystem with an endovascular prosthesis is provided. The system mayinclude an elongate outer tubular sheath having an open lumen andopposed proximal and distal ends with a medial portion therein between,the proximal end of the outer tubular sheath securably disposed to afirst handle; an elongate inner metallic hypotube having a tubular wallwith an open lumen and opposed proximal and distal ends with a medialportion therein between, the hypotube having a longitudinal lengthgreater than a longitudinal length of the outer tubular sheath, thehypotube being slidably disposed within the open lumen of the outertubular sheath, the proximal end of the hypotube securably disposed to asecond handle; a delivery guide wire slidably disposed within thehypotube, a distal end of the delivery guidewire including anendovascular prosthesis releasably disposed thereat, the distal end ofthe delivery guidewire and the endovascular prosthesis being disposedpast and beyond the distal end of the hypotube; the distal end of theouter tubular sheath being slidably disposed past and beyond the distalend of the hypotube to define an endovascular prosthesis delivery stateand slidably retractable to the medial portion of the hypotube to definean endovascular prosthesis unsheathed state; where the hypotube furtherincludes: a first flexible portion disposed from about the distal end ofthe hypotube to about the medial portion of the hypotube; a secondportion disposed from about the medial portion of the hypotube to aboutthe proximal end of the hypotube; the first flexible portion of thehypotube including a plurality of slots extending through the tubularwall of the hypotube, the slots having a circumferential arc about thetubular wall from about 150° to about 300°; and where adjacent slots areaxially offset from one and the other from about 30° to about 60°. Oneparticularly useful axial offset of the hypotube slots is about 45° sothat the rotation of the device feels smooth when placed in a tortuouspath, such as the above-described tortuous path. At axial offset anglesgreater than about 60°, rotation of the device becomes more granularwhich reduces feedback useful for accurate orientation of the deviceduring delivery through bodily lumens.

The endovascular prosthesis may be an inflatable prosthesis. In someembodiments, the inflatable endovascular prosthesis is a bifurcatedprosthesis having a tubular main body with an open end and two tubularlegs. In some embodiments, the inflatable prosthesis includes inflatablecuffs disposed at the two tubular legs and the tubular main body.Furthermore, the tubular main body may further include an expandablestent disposed at the open end of the main tubular body. The secondportion of the hypotube may be substantially free of any slots.

The hypotube may be formed from a metallic material, such as 316 or 304stainless steel. In some embodiments, the first flexible portion of thehypotube has a bending radius of at least about 1.5 inches beforeplastic deformation. The tubular wall of the hypotube may have athickness from about 0.005 inches to about 0.020 inches with an externaldiameter of the hypotube is from about 0.080 inches to about 0.260inches. Advantageously, the slots have a kerf width from about 0.001inches to about 0.003 inches.

The longitudinal distance between adjacent slots may be from about 0.010inches to about 0.050 inches and/or from about ⅙th of the exteriordiameter of the hypotube. The hypotube may have a longitudinal lengthfrom about 25 inches to about 40 inches with the flexible portion havinga longitudinal length from about 15 inches to about 32 inches and/orabout from about 50 percent to about 80 percent of the longitudinallength of the hypotube. In some embodiments, the hypotube includes anexterior surface having a surface finish of less than or equal to about32 microinches RMS. The slots may have edges that are rounded to aradius of about 0.005 inches or less.

While the outer tubular sheath may include polymeric material, such aspolytetrafluoroethylene, the hypotube is in some embodiments an uncoatedhypotube free of any polymeric covering or liner.

When the hypotube is disposed within the outer tubular sheath, thehypotube may have a torqueability from about 70% to about 100%, wherethe torqueability is measured as ratio of rotation of the distal end ofthe hypotube for a rotation amount at the proximal end of the hypotube,when placed in a tortuous path. In some embodiments, the torqueabilityof the hypotube is approximately or about 100% or a torqueability ofabout 1:1.

In some aspects of the present invention, the endovascular prosthesismay be a modular endovascular graft assembly including a bifurcated maingraft member formed from a supple graft material having a main fluidflow lumen therein. The main graft member may also include anipsilateral leg with an ipsilateral fluid flow lumen in communicationwith the main fluid flow lumen, a contralateral leg with a contralateralfluid flow lumen in communication with the main fluid flow lumen and anetwork of inflatable channels disposed on the main graft member. Thenetwork of inflatable channels may be disposed anywhere on the maingraft member including the ipsilateral and contralateral legs. Thenetwork of inflatable channels may be configured to accept a hardenablefill or inflation material to provide structural rigidity to the maingraft member when the network of inflatable channels is in an inflatedstate. The network of inflatable channels may also include at least oneinflatable cuff disposed on a proximal portion of the main graft memberwhich is configured to seal against an inside surface of a patient'svessel. The fill material can also have transient or chronic radiopacityto facilitate the placement of the modular limbs into the main graftmember. A proximal anchor member may be disposed at a proximal end ofthe main graft member and be secured to the main graft member. Theproximal anchor member may have a self-expanding proximal stent portionsecured to a self-expanding distal stent portion with struts having across sectional area that is substantially the same as or greater than across sectional area of proximal stent portions or distal stent portionsadjacent the strut. At least one ipsilateral graft extension having afluid flow lumen disposed therein may be deployed with the fluid flowlumen of the graft extension sealed to and in fluid communication withthe fluid flow lumen of the ipsilateral leg of the main graft member. Atleast one contralateral graft extension having a fluid flow lumendisposed therein may be deployed with the fluid flow lumen of the graftextension sealed to and in fluid communication with the fluid flow lumenof the contralateral leg of the main graft member. For some embodiments,an outside surface of the graft extension may be sealed to an insidesurface of the contralateral leg of the main graft when the graftextension is in a deployed state. For some embodiments, the axial lengthof the ipsilateral and contralateral legs may be sufficient to provideadequate surface area contact with outer surfaces of graft extensions toprovide sufficient friction to hold the graft extensions in place. Forsome embodiments, the ipsilateral and contralateral legs may have anaxial length of at least about 2 cm. For some embodiments, theipsilateral and contralateral legs may have an axial length of about 2cm to about 6 cm, more specifically, about 3 cm to about 5 cm.

In another aspect of the present invention, a medical device isprovided, where the medical device includes an elongate metallichypotube having an open proximal end and an opposed open distal enddefining a tubular wall having an open internal diameter and an exteriordiameter; the tubular wall have a first flexible portion disposed nearthe proximal open end and a second portion disposed near the distal openend; where the first flexible portion of the hypotube includes aplurality of slots extending through the tubular wall and having acircumferential arc from about 150° to about 300°; and where adjacentslots are axially offset from one and the other from about 30° to about60°. The second portion of the hypotube may be substantially free of anyslots.

The hypotube may be formed from a metallic material, such as 316 or 304stainless steel. In some embodiments, the first flexible portion of thehypotube has a bending radius of at least about 1.5 inches beforeplastic deformation. The tubular wall of the hypotube may have athickness from about 0.005 inches to about 0.020 inches with an externaldiameter of the hypotube is from about 0.080 inches to about 0.260inches. Advantageously, the slots have a kerf width from about 0.001inches to about 0.003 inches.

The longitudinal distance between adjacent slots may be from about 0.010inches to about 0.050 inches and/or from about ⅙ of the exteriordiameter of the hypotube. The hypotube may have a longitudinal lengthfrom about 25 inches to about 40 inches with the flexible portion havinga longitudinal length from about 15 inches to about 32 inches and/orabout from about 50 percent to about 80 percent of the longitudinallength of the hypotube. In some embodiments, the hypotube includes anexterior surface having a surface finish of less than or equal to about32 microinches RMS. The slots may have edges that are rounded to aradius of about 0.005 inches or less.

These and other features and advantages of the present invention willbecome apparent from the following detailed description of illustrativeembodiments thereof, which is to be read in connection with theaccompanying drawings. Corresponding reference element numbers orcharacters indicate corresponding parts throughout the several views ofthe drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an initial deployment state of the endovascular deliverysystem of the present invention within a patient's vasculature.

FIG. 2 depicts a deployment state of the endovascular delivery system ofthe present invention within a patient's vasculature after withdrawal ofan outer sheath.

FIG. 3 depicts a deployment state of the endovascular delivery system ofthe present invention within a patient's vasculature after an initialand partial stent deployment.

FIG. 4 depicts a deployment state of the endovascular delivery system ofthe present invention within a patient's vasculature after a stentdeployment.

FIG. 5 depicts a deployed bifurcated endovascular prosthesis with graftleg extensions.

FIG. 6 is a side elevational view of the endovascular delivery system ofthe present invention.

FIG. 7 is a side elevational and partial cutaway view of the distalportion of the endovascular delivery system of the present invention.

FIG. 8 is a partial perspective and partial cutaway view of the distalportion of the endovascular delivery system of the present invention.

FIG. 9 is a perspective view of the inner tubular member or hypotube ofthe endovascular delivery system of the present invention.

FIG. 10 is a partial perspective and cutaway view of a distal portion ofthe endovascular delivery system of the present invention showing adistal end portion of the hypotube.

FIG. 11 is a top view of the hypotube of the present invention.

FIG. 12 is a front side view of the hypotube of the present invention.

FIG. 13 is an exploded top view of the distal end of the hypotube ofFIG. 11.

FIG. 14 is a partial perspective view an axial angular offset ofadjacent slots of the hypotube of FIG. 13, taken along the 14-14 axis.

FIG. 15 is a planar schematic view of the axial angular offset of FIG.14.

FIG. 16 is a cross-section view showing a slot circumference of thehypotube of FIG. 13, taken along the 16-16 axis.

FIG. 17 is a schematic depiction of the hypotube of the presentinvention undergoing rotational torquing in a tortuous path.

FIG. 18 is a schematic depiction of the hypotube of the presentinvention undergoing deformation upon exceeding bending limits.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the invention are directed generally to methods anddevices for treatment of fluid flow vessels with the body of a patient.Treatment of blood vessels is specifically indicated for someembodiments, and, more specifically, treatment of aneurysms, such asabdominal aortic aneurysms. With regard to graft embodiments discussedherein and components thereof, the term “proximal” refers to a locationtowards a patient's heart and the term “distal” refers to a locationaway from the patient's heart. With regard to delivery system cathetersand components thereof discussed herein, the term “distal” refers to alocation that is disposed away from an operator who is using thecatheter and the term “proximal” refers to a location towards theoperator.

FIG. 1 illustrates an embodiment of a deployment sequence of anembodiment of an endovascular prosthesis (not shown), such as a modularstent graft assembly. For endovascular methods, access to a patient'svasculature may be achieved by performing an arteriotomy or cut down tothe patient's femoral artery or by other common techniques, such as thepercutaneous Seldinger technique. For such techniques, a delivery sheath(not shown) may be placed in communication with the interior of thepatient's vessel such as the femoral artery with the use of a dilatorand guidewire assembly. Once the delivery sheath is positioned, accessto the patient's vasculature may be achieved through the delivery sheathwhich may optionally be sealed by a hemostasis valve or other suitablemechanism. For some procedures, it may be necessary to obtain access viaa delivery sheath or other suitable means to both femoral arteries of apatient with the delivery sheaths directed upstream towards thepatient's aorta. In some applications a delivery sheath may not beneeded and the delivery catheter of the present invention may bedirectly inserted into the patient's access vessel by either arteriotomyor percutaneous puncture. Once the delivery sheath or sheaths have beenproperly positioned, an endovascular delivery catheter or system,typically containing an endovascular prosthesis such as but not limitedto an inflatable stent-graft, may then be advanced over a guidewirethrough the delivery sheath and into the patient's vasculature.

FIG. 1 depicts the initial placement of the endovascular delivery system100 of the present invention within a patient's vasculature. Theendovascular delivery system 100 may be advanced along a guidewire 102proximally upstream of blood flow into the vasculature of the patientincluding iliac arteries 14, 16 and aorta 10 shown in FIG. 1. While theiliac arties 14, 16 may be medically described as the right and leftcommon iliac arteries, respectively, as used herein iliac artery 14 isdescribed as an ipsilateral iliac artery and iliac artery 16 isdescribed as a contralateral iliac artery. The flow of the patient'sblood (not shown) is in a general downward direction in FIG. 1. Othervessels of the patient's vasculature shown in FIG. 1 include the renalarteries 12 and hypogastric arteries 18.

The endovascular delivery system 100 may be advanced into the aorta 10of the patient until the endovascular prosthesis (not shown) is disposedsubstantially adjacent an aortic aneurysm 20 or other vascular defect tobe treated. The portion of the endovascular delivery system 100 that isadvance through bodily lumens is in some embodiments a low profiledelivery system; for example, having an overall outer diameter of lessthan 14 French. Other diameters are also useful, such as but not limitedto less than 12 French, less than 10 French, or any sizes from 10 to 14French or greater. Once the endovascular delivery system 100 is sopositioned, an outer sheath 104 of the endovascular delivery system 100may be retracted distally so as to expose the prosthesis (not shown)which has been compressed and compacted to fit within the inner lumen ofthe outer sheath 104 of the endovascular delivery system 100.

As depicted in FIG. 2, once the endovascular delivery system 100 is sopositioned, the outer sheath 104 of the endovascular delivery system 100may be retracted distally so as to expose the endovascular prosthesis106 which has been compressed and compacted to fit within the innerlumen of the outer sheath 104 of the endovascular delivery system 100.The outer sheath 104 may be formed of a body compatible material. Insome embodiments, the biocompatible material may be a biocompatiblepolymer. Examples of suitable biocompatible polymers may include, butare not limited to, polyolefins such as polyethylene (PE), high densitypolyethylene (HDPE) and polypropylene (PP), polyolefin copolymers andterpolymers, polytetrafluoroethylene (PTFE), polyethylene terephthalate(PET), polyesters, polyamides, polyurethanes, polyurethaneureas,polypropylene and, polycarbonates, polyvinyl acetate, thermoplasticelastomers including polyether-polyester block copolymers andpolyamide/polyether/polyesters elastomers, polyvinyl chloride,polystyrene, polyacrylate, polymethacrylate, polyacrylonitrile,polyacrylamide, silicone resins, combinations and copolymers thereof,and the like. In some embodiments, the biocompatible polymers includepolypropylene (PP), polytetrafluoroethylene (PTFE), polyethyleneterephthalate (PET), high density polyethylene (HDPE), combinations andcopolymers thereof, and the like. Useful coating materials may includeany suitable biocompatible coating. Non-limiting examples of suitablecoatings include polytetrafluoroethylene, silicone, hydrophilicmaterials, hydrogels, and the like. Useful hydrophilic coating materialsmay include, but are not limited to, alkylene glycols, alkoxypolyalkylene glycols such as methoxypolyethylene oxide, polyoxyalkyleneglycols such as polyethylene oxide, polyethylene oxide/polypropyleneoxide copolymers, polyalkylene oxide-modified polydimethylsiloxanes,polyphosphazenes, poly(2-ethyl-2-oxazoline), homopolymers and copolymersof (meth)acrylic acid, poly(acrylic acid), copolymers of maleicanhydride including copolymers of methylvinyl ether and maleic acid,pyrrolidones including poly(vinylpyrrolidone) homopolymers andcopolymers of vinyl pyrrolidone, poly(vinylsulfonic acid), acryl amidesincluding poly(N-alkylacrylarnide), poly(vinyl alcohol),poly(ethyleneimine), polyamides, poly(carboxylic acids), methylcellulose, carboxymethylcellulose, hydroxypropyl cellulose,polyvinylsulfonic acid, water soluble nylons, heparin, dextran, modifieddextran, hydroxylated chitin, chondroitin sulphate, lecithin,hyaluranon, combinations and copolymers thereof, and the like.Non-limiting examples of suitable hydrogel coatings include polyethyleneoxide and its copolymers, polyvinylpyrrolidone and its derivatives;hydroxyethylacrylates or hydroxyethyl(meth)acrylates; polyacrylic acids;polyacrylamides; polyethylene maleic anhydride, combinations andcopolymers thereof, and the like. In some embodiments, the outer sheath104 may be made of polymeric materials, e.g., polyimides, polyesterelastomers (Hytrel®), or polyether block amides (Pebax®),polytetrafluoroethylene, and other thermoplastics and polymers. Theoutside diameter of the outer sheath 104 may range from about 0.1 inchto about 0.4 inch. The wall thickness of the outer sheath 104 may rangefrom about 0.002 inch to about 0.015 inch. The outer sheath 104 may alsoinclude an outer hydrophilic coating. Further, the outer sheath 104 mayinclude an internal braided or otherwise reinforced portion of eithermetallic or polymeric filaments. In addition to being radiallycompressed when disposed within an inner lumen of the outer sheath 104of the endovascular delivery system 100, a proximal stent 108 may beradially restrained by high strength flexible belts 110 in order tomaintain a small profile and avoid engagement of the proximal stent 108with a body lumen wall until deployment of the proximal stent 108 isinitiated. The belts 110 can be made from any high strength, resilientmaterial that can accommodate the tensile requirements of the beltmembers and remain flexible after being set in a constrainingconfiguration. Typically, belts 110 are made from solid ribbon or wireof a shape memory alloy such as nickel titanium or the like, althoughother metallic or polymeric materials are possible. Belts 110 may alsobe made of braided metal filaments or braided or solid filaments of highstrength synthetic fibers such as Dacron®, Spectra or the like. Anoutside transverse cross section of the belts 110 may range from about0.002 to about 0.012 inch, specifically, about 0.004 to about 0.007inch. The cross sections of belts 110 may generally take on any shape,including rectangular (in the case of a ribbon), circular, elliptical,square, etc. The ends of the belts 110 may be secured by one or morestent release wires or elongate rods 112 which extend through loopedends (not shown) of the belts 110. The stent release wires or elongaterods 112 may be disposed generally within the prosthesis 106 duringdelivery of the system 100 to the desired bodily location. For example,the stent release wires or elongate rods 112 may enter and exit theguidewire lumen 122 or other delivery system lumen as desired to affectcontrolled release of the stent 108, including if desired controlled andstaged release of the stent 108. Once the outer sheath 104 of theendovascular delivery system 100 has been retracted, the endovasculardelivery system 100 and the endovascular prosthesis 106 may be carefullypositioned in an axial direction such that the proximal stent 108 isdisposed substantially even with the renal arteries.

In some embodiments, the endovascular prosthesis 106 includes aninflatable graft 114. The inflatable graft may be a bifurcated grafthaving a main graft body 124, an ipsilateral graft leg 126 and acontralateral graft leg 128. The inflatable graft 114 may furtherinclude a fill port 116 in fluid communication with an inflation tube118 of the endovascular delivery system 100 for providing an inflationmedium (not shown). The distal portion of the endovascular deliverysystem 100 may include a nosecone 120 which provides an atraumaticdistal portion of the endovascular delivery system 100. The guidewire102 is slidably disposed within a guidewire lumen 122 of theendovascular delivery system 100.

As depicted in FIG. 3, deployment of the proximal stent 108 may beginwith deployment of the distal portion 130 of stent 108 by retracting thestent release wire or rod 112 that couples ends of belt 110 restrainingthe distal portion 130 of the stent 108. The distal portion 130 of stent108 may be disposed to the main graft body 124 via a connector ring 142.The stent 108 and/or the connector ring 142 may be made from or includeany biocompatible material, including metallic materials, such as butnot limited to, nitinol (nickel titanium), cobalt-based alloy such asElgiloy, platinum, gold, stainless steel, titanium, tantalum, niobium,and combinations thereof. The present invention, however, is not limitedto the use of such a connector ring 142 and other shaped connectors forsecuring the distal portion 130 of the stent 108 at or near the end ofthe main graft body 124 may suitably be used. Additional axialpositioning typically may be carried out even after deploying the distalportion 130 of the stent 108 as the distal portion 130 may provide onlypartial outward radial contact or frictional force on the inner lumen ofthe patient's vessel or aorta 10 until the proximal portion 132 of thestent 108 is deployed. Once the belt 110 constraining the proximalportion 132 of the stent 108 has been released, the proximal portion 132of the stent 108 self-expands in an outward radial direction until anoutside surface of the proximal portion 132 of the stent 108 makescontact with and engages an inner surface of the patient's vessel 10.

As depicted in FIG. 4, after the distal portion 130 of the stent 108 hasbeen deployed, the proximal portion 132 of the stent 108 may then bedeployed by retracting the wire 112 that couples the ends of the belt110 restraining the proximal portion 132 of the stent 108. As theproximal portion 132 of the stent 108 self-expands in an outward radialdirection, an outside surface of the proximal portion 132 of the stent108 eventually makes contact with the inside surface of the patient'saorta 10. For embodiments that include tissue engaging barbs (not shown)on the proximal portion 132 of the stent 108, the barbs may also beoriented and pushed in a general outward direction so as to make contactand engage the inner surface tissue of the patient's vessel 10, whichfurther secures the proximal stent 108 to the patient's vessel 10.

Once the proximal stent 108 has been partially or fully deployed, theproximal inflatable cuff 134 may then be filled through the inflationport 116 with inflation material injected through an inflation tube 118of the endovascular delivery system 100 which may serve to seal anoutside surface of the inflatable cuff 134 to the inside surface of thevessel 10. The remaining network of inflatable channels 136 may also befilled with pressurized inflation material at the same time whichprovides a more rigid frame like structure to the inflatable graft 114.For some embodiments, the inflation material may be a biocompatible,curable or hardenable material that may cured or hardened once thenetwork of inflatable channels 136 are filled to a desired level ofmaterial or pressure within the network or after passage of apredetermined period of time. Some embodiments may also employradiopaque inflation material to facilitate monitoring of the fillprocess and subsequent engagement of graft extensions (not shown). Thematerial may be cured by any of the suitable methods discussed hereinincluding time lapse, heat application, application of electromagneticenergy, ultrasonic energy application, chemical adding or mixing or thelike. Some embodiments for the inflation material that may be used toprovide outward pressure or a rigid structure from within the inflatablecuff 134 or network of inflatable channels 136 may include inflationmaterials formed from glycidyl ether and amine materials. Some inflationmaterial embodiments may include an in situ formed hydrogel polymerhaving a first amount of diamine and a second amount of polyglycidylether wherein each of the amounts are present in a mammal or in amedical device, such as an inflatable graft, located in a mammal in anamount to produce an in situ formed hydrogel polymer that isbiocompatible and has a cure time after mixing of about 10 seconds toabout 30 minutes and wherein the volume of said hydrogel polymer swellsless than 30 percent after curing and hydration. Some embodiments of theinflation material may include radiopaque material such as sodiumiodide, potassium iodide, barium sulfate, Visipaque 320, Hypaque,Omnipaque 350, Hexabrix and the like. For some inflation materialembodiments, the polyglycidyl ether may be selected fromtrimethylolpropane triglycidyl ether, sorbitol polyglycidyl ether,polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether,diglycerol polyglycidyl ether, glycerol polyglycidyl ether,trimethylolpropane polyglycidyl ether, polyethylene glycol diglycidylether, resorcinol diglycidyl ether, glycidyl ester ether of p-hydroxybenzoic acid, neopentyl glycol diglycidyl ether, 1,6-hexanedioldiglycidyl ether, bisphenol A (P0)₂ diglycidyl ether, hydroquinonediglycidyl ether, bisphenol S diglycidyl ether, terephthalic aciddiglycidyl ester, and mixtures thereof. For some inflation materialembodiments, the diamine may be selected from (poly)alkylene glycolhaving amino or alkylamino termini selected from the group consisting ofpolyethylene glycol (400) diamine, di-(3-aminopropyl) diethylene glycolr, polyoxypropylenediamine, polyetherdiamine, polyoxyethylenediamine,triethyleneglycol diamine and mixtures thereof. For some embodiments,the diamine may be hydrophilic and the polyglycidyl ether may behydrophilic prior to curing. For some embodiments, the diamine may behydrophilic and the polyglycidyl ether is hydrophobic prior to curing.For some embodiments, the diamine may be hydrophobic and thepolyglycidyl ether may be hydrophilic prior to curing.

The network of inflatable channels 136 may be partially or fullyinflated by injection of a suitable inflation material into the mainfill port 116 to provide rigidity to the network of inflatable channels136 and the graft 114. In addition, a seal is produced between theinflatable cuff 134 and the inside surface of the abdominal aorta 10.Although it is desirable to partially or fully inflate the network ofinflatable channels 136 of the graft 114 at this stage of the deploymentprocess, such inflation step optionally may be accomplished at a laterstage if necessary.

Once the graft 114 is deployed and the inflatable channels 136 thereofhave been filled and expanded, another delivery catheter (not shown) maybe used to deploy a contralateral graft extension 138, as depicted inFIG. 5. The contralateral graft extension 138 is in an axial positionwhich overlaps the contralateral leg 128 of the graft 114. The amount ofdesired overlap of the graft extension 138 with the contralateral leg128 may vary depending on a variety of factors including vesselmorphology, degree of vascular disease, patient status and the like.However, for some embodiments, the amount of axial overlap between thecontralateral graft extension 138 and the contralateral leg 128 may beabout 1 cm to about 5 cm; more specifically, about 2 cm to about 4 cm.Once the contralateral graft extension 138 has been deployed, anipsilateral graft extension 140 may be similarly deployed in theipsilateral graft leg 126.

For some deployment embodiments, the patient's hypogastric arteries maybe used to serve as a positioning reference point to ensure that thehypogastric arteries are not blocked by the deployment. Upon such adeployment, the distal end of a graft extension 138 or 140 may bedeployed anywhere within a length of the ipsilateral leg 126 orcontralateral leg 128 of the graft 114. Also, although only one graftextension 140, 138 is shown deployed on the ipsilateral side andcontralateral side of the graft assembly 114, additional graftextensions 140, 138 may be deployed within the already deployed graftextensions 140, 138 in order to achieve a desired length extension ofthe ipsilateral leg 126 or contralateral leg 128. For some embodiments,about 1 to about 5 graft extensions 138, 140 may be deployed on eitherthe ipsilateral or contralateral sides of the graft assembly 114.Successive graft extensions 138, 140 may be deployed within each otherso as to longitudinally overlap fluid flow lumens of successive graftextensions.

Graft extensions 138, 140, which may be interchangeable for someembodiments, or any other suitable extension devices or portions of themain graft section 124 may include a variety of suitable configurations.For some embodiments, graft extensions 138, 140 may include apolytetrafluoroethylene (PTFE) graft 142 with helical nitinol stent 144.

Further details of the endovascular prosthesis 106 and/or graftextensions 138, 140 may be found in commonly owned U.S. Pat. Nos.6,395,019; 7,081,129; 7,147,660; 7,147,661; 7,150,758; 7,615,071;7,766,954 and 8,167,927 and commonly owned U.S. Published ApplicationNo. 2009/0099649, the contents of all of which are incorporated hereinby reference in their entirety. Details for the manufacture of theendovascular prosthesis 106 may be found in commonly owned U.S. Pat.Nos. 6,776,604; 7,090,693; 7,125,464; 7,147,455; 7,678,217 and7,682,475, the contents of all of which are incorporated herein byreference in their entirety. Useful inflation materials for theinflatable graft 114 may be found in may be found in commonly owned U.S.Published Application No. 2005/0158272 and 2006/0222596, the contents ofall of which are incorporated herein by reference in their entirety.Additional details concerning delivery details, including systems,devices and methods, of the ipsilateral graft leg 126 and thecontralateral leg 128 may be found in commonly owned U.S. ProvisionalApplication No. 61/660,105, entitled “Bifurcated Endovascular ProsthesisHaving Tethered Contralateral Leg”, filed Jun. 15, 2012, and havingAttorney Docket No. 1880-44P, the contents of which are incorporated theherein by reference in their entirety. Additional details of anendovascular delivery system having an improved radiopaque marker systemfor accurate prosthesis delivery may be found in commonly owned U.S.Provisional Application No. 61/660,413, entitled “Endovascular DeliverySystem With An Improved Radiopaque Marker Scheme”, filed Jun. 15, 2012,and having Attorney Docket No. 1880-42P, the contents of which areincorporated the herein by reference in their entirety.

Useful graft materials for the endovascular prosthesis 106 include, butare not limited, polyethylene; polypropylene; polyvinyl chloride;polytetrafluoroethylene (PTFE); fluorinated ethylene propylene;fluorinated ethylene propylene; polyvinyl acetate; polystyrene;poly(ethylene terephthalate); naphthalene dicarboxylate derivatives,such as polyethylene naphthalate, polybutylene naphthalate,polytrimethylene naphthalate and trimethylenediol naphthalate;polyurethane, polyurea; silicone rubbers; polyamides; polyimides;polycarbonates; polyaldehydes; polyether ether ketone; natural rubbers;polyester copolymers; silicone; styrene-butadiene copolymers;polyethers; such as fully or partially halogenated polyethers; andcopolymers and combinations thereof. In some embodiments, the graftmaterials are non-textile graft materials, e.g., materials that are notwoven, knitted, filament-spun, etc. that may be used with textilegrafts. Such useful graft material may be extruded materials.Particularly useful materials include porous polytetrafluoroethylenewithout discernable node and fibril microstructure and (wet) stretchedPTFE layer having low or substantially no fluid permeability thatincludes a closed cell microstructure having high density regions whosegrain boundaries are directly interconnected to grain boundaries ofadjacent high density regions and having substantially no node andfibril microstructure , and porous PTFE having no or substantially nofluid permeability. Such PTFE layers may lack distinct, parallel fibrilsthat interconnect adjacent nodes of ePTFE, typically have no discernablenode and fibril microstructure when viewed at a magnification of up to20,000. A porous PTFE layer having no or substantially no fluidpermeability may have a Gurley Number of greater than about 12 hours, orup to a Gurley Number that is essentially infinite, or too high tomeasure, indicating no measurable fluid permeability. Some PTFE layershaving substantially no fluid permeability may have a Gurley Number at100 cc of air of greater than about 10⁶ seconds. The Gurley Number isdetermined by measuring the time necessary for a given volume of air,typically, 25 cc, 100 cc or 300 cc, to flow through a standard 1 squareinch of material or film under a standard pressure, such as 12.4 cmcolumn of water. Such testing maybe carried out with a GurleyDensometer, made by Gurley Precision Instruments, Troy, N.Y. Details ofsuch useful PTFE materials and methods for manufacture of the same maybe found in commonly owned U.S. Patent Application Publication No.2006/0233991, the contents of which are incorporated herein by referencein their entirety.

FIG. 6 is a side elevational view of the endovascular delivery system100 of the present invention. The endovascular delivery system 100 mayinclude, among other things, the nosecone 120; the outer sheath 104; aretraction knob or handle 152 for the outer sheath 104; a flush port 154for the outer sheath 104; an outer sheath radiopaque marker band 156; aninner tubular member or hypotube 150; an inflation material or polymerfill connector port 158; an inflation material or polymer fill cap 160;a guidewire flush port 162; a guidewire flush port cap 164; a guidewireport 166; and nested stent release knobs 168; interrelated as shown.

The flush port 154 for the outer sheath 104 may be used to flush theouter sheath 104 during delivery stages. The outer sheath 104 may have aradiopaque marker band to aid the practitioner in properly navigatingthe delivery system 100 to the desired bodily site. The outer sheath 104is retractable by movement of the retraction knob or handle 152 for theouter sheath 104 by a practitioner towards the proximal handle assembly170 of the delivery system 100. The inner tubular member or hypotube 150is disposed from the inner tubular member or hypotube 150 toward aproximal portion of the delivery system 100. The inflation material orpolymer fill connector port 158 and the inflation material or polymerfill cap 160 are useful for providing inflation material (e.g.,polymeric fill material) to inflate proximal inflatable cuffs 134 andthe network of inflatable channels 136 of the inflatable graft 114. Theguidewire flush port 162 and the guidewire flush port cap 164 are usefulfor flushing the guidewire port 166 during delivery stages of thedelivery system 100. The nested stent release knobs 168 contains aseries of nested knobs (not shown) that that are used to engage releasemechanisms for delivery of the endovascular prosthesis 106. Furtherdetails, including but not limited to methods, catheters and systems,for deployment of endovascular prostheses are disclosed in commonlyowned U.S. Pat. Nos. 6,761,733 and 6,733,521 and commonly owned U.S.Patent Application Publication Nos. 2006/0009833 and 2009/0099649, allof which are incorporated by reference herein in their entirety.

FIG. 7 is a side elevational and partial cutaway view of the distalportion 172 of the endovascular delivery system 100 of the presentinvention, and FIG. 8 is a partial perspective and partial cutaway viewof the distal portion 172 of the endovascular delivery system 100 of thepresent invention. The distal portion 172 of the endovascular deliverysystem 100 includes prosthesis/stent holders 174 disposed upon aprosthesis/stent holder guidewire 176. The holders 174 are usefulreleasably securing the endovascular prosthesis 106 (not shown) withinthe delivery system 100. The holders 174 inhibit or substantiallyinhibit undesirable longitudinal and/or circumferential movement of theendovascular prostheses 106 during delivery stages of the deliverysystem 100. Belts 110 serve to restrain the endovascular prosthesis 106in a radially constrained stage until desired release of theendovascular prosthesis 106.

FIG. 9 is a perspective view of an embodiment of the inner tubularmember or hypotube 150 of the endovascular delivery system 100 of thepresent invention, and FIG. 10 is a partial perspective and cutaway viewof a distal portion 172 of an embodiment of the endovascular deliverysystem 100 of the present invention showing a distal end 178 of thehypotube 150. The hypotube has an open lumen 186 and opposed distal end178 and proximal end 184 with a medial portion 182 therein between. Theproximal end 184 of the hypotube 150 is securable disposed to theproximal handle assembly 170. The distal end 178 of the hypotube 150 hasa cap 188 through which the inflation tube 118, the guidewire lumen 122and the prosthesis/stent holders guidewire 176 passes there throughi.e., from the proximal handle assembly 170 and through the open lumen186 of the hypotube 150. The cap 188 may be made from any polymeric orplastic material. Polycarbonate is an example of one useful material forthe cap 188. The guidewire lumen 122 may be made from polymericmaterials such as polyimide, polyethylene, polyetheretherketones(PEEK™), or other suitable polymers. The guidewire lumen 122 may have anoutside diameter ranging from about 0.02 inch to about 0.08 inch and awall thickness may range from about 0.002 inch to about 0.025 inch.Other lumens disposed within the lumen 186 of the hypotube 150 may bemade from similar materials.

FIG. 11 is a top view of the hypotube of an embodiment of the presentinvention, and FIG. 12 is a front side view of an embodiment of thehypotube of the present invention. As depicted in FIGS. 11 and 12 theproximal and distal ends 184, 178 of the hypotube 150 have end slots 190and end holes 192. Such end slots 190 and end holes 192 are useful forsecuring the proximal end 184 of the hypotube 150 to the proximal handleassembly 170 and for securing the distal end 178 of the hypotube 150 tothe distal cap 188 of the hypotube 150. The end slots 190 are alsouseful for aligning the handle 170 to the device 100 such that thehandle fill port 158 and the hypotube 150 are in the same plane but areoffset at about 180° from each other.

FIG. 13 is an exploded top view of the distal end of the hypotube ofFIG. 11. As depicted in FIG. 13, the slots 180 may have a slot kerf D₂width from about 0.0005 inches to about 0.0030 inches. In someembodiments, the slot kerf D₂ width is from about 0.0010 inches to about0.0020 inches, more preferably about 0.0015±0.0010 inches. Thelongitudinal distance D₁ between adjacent slots 180 may be from about0.010 inches to about 0.050 inches, preferably about 0.025±0.001 inches,or about 1/6 of the external diameter of the hypotube 150. Suchdimensions are useful, for among other things, for a delivery systemhaving an overall profile of about 14 French or less. The longitudinaldistance D₁ may be increased to about 0.033 inches, allowing a reductionin the number of slots to reduce the cost and complexity ofmanufacturing the hypotube 150. The circumferential arc of the slots 180(as represented by angle β in FIG. 16) may be varied to obtain usefulflexibility and torque performance or characteristics. Generally,increasing the circumferential arc will increase flexibility and torqueperformance or characteristics. The external diameter of the hypotube150 may be from about 0.080 inches to about 0.260 inches, preferablyabout 0.156±0.001 inches. This external diameter is useful, for example,with delivery profiles of about 14 French or less and is non-limiting.Other external diameters may suitably be used. For example, one usefulexternal diameter is about 0.134±0.001 inches for an overall low profileof about 12 French or less. The hypotube 150 may have a lumen wallthickness from about 0.005 inches to about 0.020 inches, including fromabout 0.005±0.001 inches to about 0.010±0.001 inches, and ±0.001. Insome embodiments, the internal diameter of the hypotube 150 may be about0.136±0.001 inches, resulting in a 0.010±0.001 inch wall thickness. Thiswall thickness is useful, for example, with delivery profiles of about14 French or less and is non-limiting. Other wall thicknesses maysuitably be used. For example, another useful thinner wall thickness of0.005±0.001 inch may be used for an overall low profile of about 12French or less. The overall longitudinal length of the hypotube 150 mayvary from about 25 inches to about 40 inches. The overall longitudinallength of the flexible portion of the hypotube 150 having the slots 180may vary from about 15 inches to about 32 inches.

FIG. 14 is a partial perspective view an axial angular offset ofadjacent slots of the hypotube of FIG. 13, taken along the 14-14 axis;and FIG. 15 is a planar schematic view of the axial angular offset ofFIG. 14. In FIG. 15 the nominal circumference of the hypotube 150 isshown in outline by the dashed circle C₁. As depicted in FIGS. 14 and15, adjacent slots 180 a, 180 b may be axially offset at an angle α fromone and the other from about 30° to about 120°; preferably, from about30° to about 90°; more preferably, from about 40° to about 50°. Theaxially offset angle α is defined as the angle between the slot endportions of the adjacent slots 180 a, 180 b from the longitudinal axisL₁ of the hypotube 150 as depicted by axes Ya, Yb, respectively. Oneuseful axially offset angle α is about 45° for smooth rotation whenplaced in a tortuous path, such as tortuous path 198 described below inconjunction with FIG. 17.

FIG. 16 is a cross-section view showing a slot circumference of thehypotube of FIG. 13, taken along the 16-16 axis. As depicted in FIG. 16,the slots 180 may have a circumferential arc represented by an angle βfrom about 150° to about 300°. One useful circumferential arc or anangle β is about 220°±5°. This angle β is useful, but not limited to,for use with a wall thickness of about 0.010±0.001 inches. For thinnerwall thicknesses, for example about 0.005±0.001 inches, a lower angle βof about 170°±5° may be used. Portions of the tubular wall 194 of thehypotube 150 that are outside of the circumferential arc of the slot 180are shown in cross-hatch in FIG. 16.

While the slots 180 of the hypotube 150 have been described as beingcircumferential arcs, the present invention is not so limiting. Theslots 180 may be, for example, generally circumferential. Such a generalcircumferential orientation may include a longitudinal extent along thelongitudinal axis L₁ of the hypotube along with a circumferential extentalong radial axis, C₁. In other words, a generally circumferential mayinclude a helical orientation of the slots 180. Furthermore, the arcsthemselves of the slots 180 may have different orientations, such as butnot limited to a combination of circumferential and/or helical arcsincluding interleaving patterns, such as where the arcs or portions ofthe arcs may crisscross or be in a pattern of dual or more opposinghelixes. Still furthermore, the slots 180 themselves may be angledthrough the wall of the hypotube 150. Moreover, portions of the slots180 may not extend entirely through the wall of the hypotube 150, butmay only extend partially from the outer surface of the hypotube 150towards the inner surface of the hypotube 150, or vice versa, e.g. be apartial slot extending though only a portion of the hypotube wall wherethe slot opening stats at the outer surface of the hypotube, at theinner surfaces of the hypotube, or combinations thereof.

The hypotube 150 is in some embodiments an uncoated hypotube free of anypolymeric covering or liner. One useful metallic material for thehypotube 150 may be 316 or 304 stainless steel. Other biocompatiblematerials may suitably be used, such as but not limited to, nitinol,cobalt-based alloy such as Elgiloy, platinum, gold, titanium, tantalum,niobium, and combinations thereof. The hypotube 150 may have a smoothexterior surface, such as one having a surface finish of less than orequal to about 32 microinches RMS. RMS is a measure of the smoothness ofa surface. RMS refers to the Root Mean Square (RMS) of the average ofmeasured peaks and valleys of a material surface profile calculated froma number of measurements along a sample length or area. Such RMS valuesare typically measured pursuant to ASTM D7127-015, the contents of whichare incorporated herein by reference. RMS values from about 16microinches to about 32 microinches are also useful. Moreover, the slots180 have edges that are rounded to a radius of about 0.005 inches orless.

The hypotube 150 is in some embodiments may have a polymeric covering orliner. In some embodiments the polymeric covering or liner may be apolymer coating or a polymer extrusion. A polymer extrusion may coverthe slit or slot 180 edges under bending. Such a covering significantlyreduces the unsheathing forces in a tortuous path as compared to anuncoated hypotube and also provides hemostasis as the hypotube 150 is ofthe delivery system 100. A polymer coating will generally not cover theedges of the slits or slots 180. Such a polymer coating will reduce theunsheathing forces in a tortuous path as compared to an uncoatedhypotube, but generally to a lesser degree as compared to a hypotubehaving the polymer extrusion. A hypotube with the polymer coating maynot provide the degree of hemostasis as compared to the hypotube havingthe polymer extrusion. Both the hypotube having the polymer extrusionand the hypotube having the polymer coating will reduce the frictionforce through the flush port valve of the system 100, which also tendsto reduce the unsheathing force. A hypotube with an inner polymer liner,which may be a polymer extrusion and/or a polymer coating, may be usedto address or provide hemostasis.

Useful extrusion polymers include, but are not limited to,polytetrafluoroethylene (PTFE), ethylenetetrafluoroethylene (ETFE),fluorinated ethylene propylene (FEP), perfluoroalkoxy (PFA),polyethylene terephthalate (PET) and polyethylene co-extrusions. Theseextrusions polymers are heat-shrinkable. Useful thicknesses of theextrusion polymers include, but are not limited to, from about 0.0005inches to about 0.002 inches. The thickness of the polymer coating maybe less than about 0.0005 inches. The polymer coating may not actuallycover the slits or slots 180, so as compared a hypotube having thepolymer extrusion where the slit or slot 180 are covered, the polymercoated hypotube is not as “smooth” especially when hypotube is bent.Useful polymer coatings include, but are not limited to also,polytetrafluoroethylene (PTFE) and poly(p-xylylene) polymers (Parylene).Moreover, the hypotube 150 may be electro-polished to round the slit orslot edges, which also improves hypotube performance.

FIG. 17 is a schematic depiction of the hypotube of the presentinvention undergoing rotational torquing in a tortuous path 198. Thetortuous path 198 is depicted in FIG. 17 as an S-shaped path having twofull and opposed 180° bends with a bend radius R₁ of about 2 inches.With the hypotube 150 being disposed within the outer tubular sheath104, the hypotube 150 has a torqueability from about 70% to about 100%when disposed in such a tortuous path 198. The torqueability is measuredas percent of rotation of the distal end 178; i.e., angle θ1, of thehypotube 150 for a rotation amount at the proximal end 184; i.e., angleθ2, of the hypotube 150 when placed in the tortuous path 198. In someembodiments, the hypotube 150 has a torqueability of about 1:1 or 100%when disposed in such a tortuous path 198.

FIG. 18 is a schematic depiction of the hypotube of the presentinvention undergoing plastic deformation upon exceeding bending limits.As illustrated in FIG. 18, when the flexible portion of the hypotube 150having the slots 180 is bent beyond a bending radius R₂ the material ofthe hypotube in the vicinity of certain slots, such as slots 200, maybecome plastically deformed. Such plastically deformation may preventslots 200 returning completely to their original shape and orientationwith the hypotube 150 after removal of a bending or other force. In someembodiments, the hypotube of the present invention has a bending radiusR₂ of at least about 1.5 inches or no more than about 105 inches beforeportions of it may experience plastic deformation.

While various embodiments of the present invention are specificallyillustrated and/or described herein, it will be appreciated thatmodifications and variations of the present invention may be effected bythose skilled in the art without departing from the spirit and intendedscope of the invention. Further, any of the embodiments or aspects ofthe invention as described in the claims or in the specification may beused with one and another without limitation.

The following embodiments or aspects of the invention may be combined inany fashion and combination and be within the scope of the presentinvention, as follows:

-   Embodiment 1. An endovascular delivery system, comprising:    -   an elongate outer tubular sheath having an open lumen and        opposed proximal and distal ends with a medial portion therein        between;    -   an elongate inner metallic hypotube having a tubular wall with        an open lumen and opposed proximal and distal ends with a medial        portion therein between, the hypotube having a longitudinal        length greater than a longitudinal length of the outer tubular        sheath, the hypotube being slidably disposed within the open        lumen of the outer tubular sheath;    -   the distal end of the outer tubular sheath being slidably        disposed past and beyond the distal end of the hypotube to        define an endovascular prosthesis delivery state and slidably        retractable to the medial portion of the hypotube to define an        endovascular prosthesis unsheathed state;    -   wherein the hypotube further comprises:    -   a first flexible portion disposed from about the distal end of        the hypotube to about the medial portion of the hypotube;    -   a second portion disposed from about the medial portion of the        hypotube to about the proximal end of the hypotube;    -   the first flexible portion of the hypotube comprising a        plurality of slots extending through the tubular wall of the        hypotube, said slots having a circumferential arc about the        tubular wall from about 150° to about 300°; and    -   wherein adjacent slots are axially offset from one and the other        from about 30° to about 60°.-   Embodiment 2. The endovascular delivery system of embodiment 1,    wherein said hypotube is formed from a metallic material comprising    316 or 304 stainless steel.-   Embodiment 3. The endovascular delivery system of embodiment 1,    wherein the first flexible portion of the hypotube has a bending    radius of no more than about 1.5 inches before plastic deformation.-   Embodiment 4. The endovascular delivery system of embodiment 1,    wherein the tubular wall of the hypotube has a thickness from about    0.005 inches to about 0.020 inches.-   Embodiment 5. The endovascular delivery system of embodiment 1,    wherein the external diameter of the hypotube is from about 0.080    inches to about 0.260 inches.-   Embodiment 6. The endovascular delivery system of embodiment 1,    wherein the slots have a kerf width from about 0.001 inches to about    0.003 inches.-   Embodiment 7. The endovascular delivery system of embodiment 1,    wherein a longitudinal distance between adjacent slots is from about    0.010 inches to about 0.050 inches.-   Embodiment 8. The endovascular delivery system of embodiment 1,    wherein a longitudinal distance between adjacent slots is from about    ⅙ of the exterior diameter of the hypotube.-   Embodiment 9. The endovascular delivery system of embodiment 1,    wherein the hypotube comprises an exterior surface having a surface    finish of less than or equal to about 32 microinches RMS.-   Embodiment 10. The endovascular delivery system of embodiment 1,    wherein the hypotube has a longitudinal length from about 25 inches    to about 40 inches; and further wherein the flexible portion has a    longitudinal length from about 15 inches to about 32 inches.-   Embodiment 11. The endovascular delivery system of embodiment 1,    wherein the hypotube has a longitudinal length; and further wherein    the flexible portion has a longitudinal length from about 50 percent    to about 80 percent of the longitudinal length of the hypotube.-   Embodiment 12. The endovascular delivery system of embodiment 1,    wherein the slots have edges that are rounded to a radius of about    0.005 inches or less.-   Embodiment 13. The endovascular delivery system of embodiment 1,    wherein the outer tubular sheath comprises polytetrafluoroethylene.-   Embodiment 14. The endovascular delivery system of embodiment 1,    wherein the hypotube is an uncoated hypotube free of any polymeric    covering or liner.-   Embodiment 15. The endovascular delivery system of embodiment 1,    wherein, when the hypotube is disposed within the outer tubular    sheath, the hypotube has a torqueability from about 70% to about    100%, said torqueability being measured as percent of rotation of    the distal end of the hypotube for a rotation amount at the proximal    end of the hypotube when placed in a tortuous path-   Embodiment 16. The endovascular delivery system of embodiment 1,    wherein, when the hypotube is disposed within the outer tubular    sheath, the hypotube has a torqueability of about 1:1, said    torqueability being measured as ratio of rotation of the distal end    of the hypotube for a rotation amount at the proximal end of the    hypotube, when placed in tortuous path.-   Embodiment 17. The endovascular delivery system of embodiment 1,    wherein the second portion of the hypotube is substantially free of    any slots.-   Embodiment 18. An endovascular delivery system, comprising:    -   an elongate outer tubular sheath having an open lumen and        opposed proximal and distal ends with a medial portion therein        between, the proximal end of the outer tubular sheath securably        disposed to a first handle;    -   an elongate inner metallic hypotube having a tubular wall with        an open lumen and opposed proximal and distal ends with a medial        portion therein between, the hypotube having a longitudinal        length greater than a longitudinal length of the outer tubular        sheath, the hypotube being slidably disposed within the open        lumen of the outer tubular sheath, the proximal end of the        hypotube securably disposed to a second handle;    -   a delivery guide wire slidably disposed within the hypotube, a        distal end of the delivery guidewire including an endovascular        prosthesis releasably disposed thereat, said distal end of the        delivery guidewire and said endovascular prosthesis being        disposed past and beyond the distal end of the hypotube;    -   the distal end of the outer tubular sheath being slidably        disposed past and beyond the distal end of the hypotube to        define an endovascular prosthesis delivery state and slidably        retractable to the medial portion of the hypotube to define an        endovascular prosthesis unsheathed state;    -   wherein the hypotube further comprises:    -   a first flexible portion disposed from about the distal end of        the hypotube to about the medial portion of the hypotube;    -   a second portion disposed from about the medial portion of the        hypotube to about the proximal end of the hypotube;    -   the first flexible portion of the hypotube comprising a        plurality of slots extending through the tubular wall of the        hypotube, said slots having a circumferential arc about the        tubular wall from about 150° to about 300°; and    -   wherein adjacent slots are axially offset from one and the other        from about 30° to about 60°.-   Embodiment 19. The endovascular delivery system of embodiment 18,    wherein said endovascular prosthesis is an inflatable prosthesis.-   Embodiment 20. The endovascular delivery system of embodiment 19,    wherein said inflatable endovascular prosthesis is a bifurcated    prosthesis having a tubular main body with an open end and two    tubular legs.-   Embodiment 21. The endovascular delivery system of embodiment 20,    wherein said inflatable prosthesis comprises inflatable cuffs    disposed at said two tubular legs and said tubular main body.-   Embodiment 22. The endovascular delivery system of embodiment 21,    wherein said tubular main body further comprises an expandable stent    disposed at said open end of said main tubular body.-   Embodiment 23. The endovascular delivery system of embodiment 18,    wherein said hypotube is formed from a metallic material comprising    316 or 304 stainless steel.-   Embodiment 24. The endovascular delivery system of embodiment 18,    wherein the first flexible portion of the hypotube has a bending    radius of no more than about 1.5 inches before plastic deformation.-   Embodiment 25. The endovascular delivery system of embodiment 18,    wherein the tubular wall of the hypotube has a thickness from about    0.005 inches to about 0.020 inches.-   Embodiment 26. The endovascular delivery system of embodiment 18,    wherein the external diameter of the hypotube is from about 0.080    inches to about 0.260 inches.-   Embodiment 27. The endovascular delivery system of embodiment 18,    wherein the slots have a kerf width from about 0.001 inches to about    0.003 inches.-   Embodiment 28. The endovascular delivery system of embodiment 18,    wherein a longitudinal distance between adjacent slots is from about    0.010 inches to about 0.050 inches.-   Embodiment 29. The endovascular delivery system of embodiment 18,    wherein a longitudinal distance between adjacent slots is from about    ⅙ of the exterior diameter of the hypotube.-   Embodiment 30. The endovascular delivery system of embodiment 18,    wherein the hypotube comprises an exterior surface having a surface    finish of less than or equal to about 32 microinches RMS.-   Embodiment 31. The endovascular delivery system of embodiment 18,    wherein the hypotube has a longitudinal length from about 25 inches    to about 40 inches; and further wherein the flexible portion has a    longitudinal length from about 15 inches to about 32 inches.-   Embodiment 32. The endovascular delivery system of embodiment 18,    wherein the hypotube has a longitudinal length; and further wherein    the flexible portion has a longitudinal length from about 50 percent    to about 80 percent of the longitudinal length of the hypotube.-   Embodiment 33. The endovascular delivery system of embodiment 18,    wherein the slots have edges that are rounded to a radius of about    0.005 inches or less.-   Embodiment 34. The endovascular delivery system of embodiment 18,    wherein the outer tubular sheath comprises polytetrafluoroethylene.-   Embodiment 35. The endovascular delivery system of embodiment 18,    wherein the hypotube is an uncoated hypotube free of any polymeric    covering or liner.-   Embodiment 36. The endovascular delivery system of embodiment 18,    wherein, when the hypotube is disposed within the outer tubular    sheath, the hypotube has a torqueability from about 70% to about    100%, said torqueability being measured as percent of rotation of    the distal end of the hypotube for a rotation amount at the proximal    end of the hypotube when placed on tortuous path.-   Embodiment 37. The endovascular delivery system of embodiment 18,    wherein, when the hypotube is disposed within the outer tubular    sheath, the hypotube has a torqueability of about 1:1, said    torqueability being measured as ratio of rotation of the distal end    of the hypotube for a rotation amount at the proximal end of the    hypotube when placed on tortuous path.-   Embodiment 38. The endovascular delivery system of embodiment 18,    wherein the second portion of the hypotube is substantially free of    any slots.-   Embodiment 39. A medical device comprising:-   an elongate metallic hypotube having an open proximal end and an    opposed open distal end defining a tubular wall having an open    internal diameter and an exterior diameter; said tubular wall have a    first flexible portion disposed near the proximal open end and a    second portion disposed near the distal open end;-   wherein the first flexible portion of the hypotube comprises a    plurality of slots extending through the tubular wall and having a    circumferential arc from about 150° to about 300°; and-   wherein adjacent slots are axially offset from one and the other    from about 30° to about 60°.-   Embodiment 40. The medical device of embodiment 39, wherein the    hypotube comprises a metallic material.-   Embodiment 41. The medical device of embodiment 40, wherein the    metallic material comprises stainless steel.-   Embodiment 42. The medical device of embodiment 40, wherein the    metallic material is 316 or 304 stainless steel.-   Embodiment 43. The medical device of embodiment 39, wherein the    first flexible portion of the hypotube has a bending radius of no    more than about 1.5 inches before plastic deformation.-   Embodiment 44. The medical device of embodiment 39, wherein the    tubular wall has a thickness from about 0.005 inches to about 0.020    inches.-   Embodiment 45. The medical device of embodiment 39, the external    diameter of the hypotube is from about 0.080 inches to about 0.260    inches.-   Embodiment 46. The medical device of embodiment 39, wherein the    slots have a kerf width from about 0.001 inches to about 0.003    inches.-   Embodiment 47. The medical device of embodiment 39, wherein a    longitudinal distance between adjacent slots is from about 0.010    inches to about 0.050 inches.-   Embodiment 48. The medical device of embodiment 39, wherein a    longitudinal distance between adjacent slots is from about ⅙ of the    exterior diameter of the hypotube.-   Embodiment 49. The medical device of embodiment 39, wherein the    hypotube comprises an exterior surface having a surface finish of    less than or equal to about 32 microinches RMS.-   Embodiment 50. The medical device of embodiment 39, wherein the    hypotube has a longitudinal length from about 25 inches to about 40    inches; and further wherein the flexible portion has a longitudinal    length from about 15 inches to about 32 inches.-   Embodiment 51. The medical device of embodiment 39, wherein the    hypotube has a longitudinal length; and further wherein the flexible    portion has a longitudinal length from about 50 percent to about 80    percent of the longitudinal length of the hypotube.-   Embodiment 52. The medical device of embodiment 39, wherein the    slots have edges that are rounded to a radius of about 0.005 inches    or less.-   Embodiment 53. The medical device of embodiment 39, wherein the    second portion of the hypotube is substantially free of any slots.

1.-27. (canceled)
 28. An endovascular delivery system, comprising: anelongate outer tubular sheath having an open lumen and opposed proximaland distal ends with a medial portion therein between; an elongate innermetallic hypotube having a tubular wall with an open lumen and opposedproximal and distal ends with a medial portion therein between, thehypotube having a longitudinal length greater than a longitudinal lengthof the outer tubular sheath, the hypotube being slidably disposed withinthe open lumen of the outer tubular sheath; the distal end of the outertubular sheath being slidably disposed past and beyond the distal end ofthe hypotube to define an endovascular prosthesis delivery state andslidably retractable to the medial portion of the hypotube to define anendovascular prosthesis unsheathed state; wherein the hypotube furthercomprises: a first flexible portion disposed from about the distal endof the hypotube to about the medial portion of the hypotube; a secondportion disposed from about the medial portion of the hypotube to aboutthe proximal end of the hypotube; the first flexible portion of thehypotube comprising a plurality of slots extending through the tubularwall of the hypotube, said slots having a circumferential arc about thetubular wall from about 150° to about 300°; wherein adjacent slots areaxially offset from one and the other from about 30° to about 60°;wherein at least one end of the hypotube includes a hole for securementto the delivery system proximal to that end; and wherein the hypotubehas a polymeric covering of a polymer coating or a polymer extrusion.29. The endovascular delivery system of claim 28, wherein the polymericcoating is selected from the group consisting of polytetrafluoroethylene(PTFE) and poly(p-xylylene) polymers (Parylene).
 30. The endovasculardelivery system of claim 28, wherein a thickness of the polymer coatingis less than about 0.0005 inches.
 31. The endovascular delivery systemof claim 28, wherein the polymer extrusion includes polymers selectedfrom the group consisting of polytetrafluoroethylene (PTFE),ethylenetetrafluoroethylene (ETFE), fluorinated ethylene propylene(FEP), perfluoroalkoxy (PFA), polyethylene terephthalate (PET) andpolyethylene co-extrusions.
 32. The endovascular delivery system ofclaim 28, wherein the polymer extrusion includes heat-shrinkablepolymers.
 33. The endovascular delivery system of claim 28, wherein athickness of the polymer extrusion is from about 0.0005 inches to about0.002 inches.
 34. The endovascular delivery system of claim 28, whereinthe polymer coating or the polymer extrusion covers the slots.
 35. Theendovascular delivery system of claim 28, wherein the polymer coating orthe polymer extrusion does not cover the slots.
 36. The endovasculardelivery system of claim 28, wherein said hypotube is formed from ametallic material comprising 316 or 304 stainless steel.
 37. Theendovascular delivery system of claim 28, wherein said hypotube isformed from a biocompatible material selected from the group consistingof nitinol, cobalt-based alloy, platinum, gold, titanium, tantalum,niobium, and combinations thereof.
 38. The endovascular delivery systemof claim 28, wherein the hypotube comprises an exterior surface having asurface finish of less than or equal to about 32 microinches RMS
 39. Theendovascular delivery system of claim 28, wherein the tubular wall ofthe hypotube has a thickness from about 0.005 inches to about 0.020inches.
 40. The endovascular delivery system of claim 28, wherein theslots have a kerf width from about 0.001 inches to about 0.003 inches.41. The endovascular delivery system of claim 28, wherein a longitudinaldistance between adjacent slots is from about 0.010 inches to about0.050 inches.
 42. The endovascular delivery system of claim 28, whereinthe slots have edges that are rounded to a radius of about 0.005 inchesor less.
 43. The endovascular delivery system of claim 28, wherein theouter tubular sheath comprises polytetrafluoroethylene.
 44. Theendovascular delivery system of claim 28, wherein, when the hypotube isdisposed within the outer tubular sheath, the hypotube has atorqueability from about 70% to about 100%, said torqueability beingmeasured as percent of rotation of the distal end of the hypotube for arotation amount at the proximal end of the hypotube when placed in atortuous path.
 45. The endovascular delivery system of claim 28, whereinthe first flexible portion of the hypotube has a bending radius of nomore than about 1.5 inches before plastic deformation.
 46. Theendovascular delivery system of claim 28, wherein the hole of the atleast one end of the hypotube is disposed at a proximal portion of thehypotube to secure the hypotube to a proximal handle assembly.
 47. Theendovascular delivery system of claim 28, wherein the hole of the atleast one end of the hypotube is disposed at a distal portion of thehypotube to secure the hypotube to a distal cap of the hypotube.